Idiopathic tremor is an autosomal dominant disorder, the most common extrapyramidal disorder, and the most common tremor disorder, with a family history in approximately 60% of patients. Idiopathic tremor is a single-symptom disorder, and postural tremor is the only clinical manifestation of the disease. The so-called postural tremor is a tremor that is triggered when the limb is maintained in a certain posture, and it disappears naturally when the limb is completely relaxed. The tremor is triggered when the limb is in a certain posture and disappears naturally when the limb is completely relaxed.
Clinical manifestations
Essential tremor ET, also known as familial or benign idiopathic tremor, is a common clinical movement disorder with autosomal dominant inheritance, in which postural or motor tremor is the only manifestation and progresses slowly or does not progress for a long time. Age is now considered to be an important risk factor for ET and the prevalence increases with age. The onset of the disease is slow. It can develop at any age, but most often begins in adults, with slightly more males than females reported in the literature.
Tremor in this disease is common in the hands, followed by tremor in the head, and in very few patients, tremor in the lower extremities. The tremor in this disease is aggravated by concentration, nervousness, fatigue, and hunger. In most cases, it disappears temporarily after drinking alcohol and worsens the next day, which is also characteristic of idiopathic tremor. It should be treated symptomatically.
Epidemiology
The prevalence of idiopathic tremor in the general population is 0.3% to 1.7%, and increases with age. The prevalence increases to 5.5% in people older than 40 years of age and 10.2% in people older than 65 years of age with no significant difference between men and women. In Finland, the prevalence rate of 5.55% in people over 40 years of age was reported in the literature; the prevalence rate of 12.6% in people aged 70-79 years in Mississippi was 10 times higher than that of people aged 40-69 years.
Symptoms and signs
The disease most often develops in the late teens or early adulthood, and tremor is the only clinical symptom, manifesting as postural or motor tremor, often involving one or both hands or the head, and the symptoms do not become apparent until later. In some cases, the tremor may prevent the hand from completing fine motor movements such as writing, and may affect articulation when the laryngeal muscles are involved, while the lower extremities are not involved. Patients often report that a small amount of alcohol can provide significant relief, but this is short-lived and the mechanism is unclear. There are usually no other neurological signs on examination.
Diagnosis
Idiopathic tremor grading
Idiopathic tremor should be considered based on the patient’s frequent presence of postural and/or motor tremor that decreases with alcohol consumption, a family history, and the absence of other neurologic signs and symptoms.
Clinical grading of tremor The clinical grading of tremor proposed by the National Institutes of Health (NIH) Idiopathic Tremor Study Group in 1996 is 5 grades.
Grade 0: No tremor.
Grade I: very mild tremor (not easily detected).
Grade II: easily detectable tremor of less than 2 cm in amplitude without disabling tremor.
Grade III: obvious amplitude 2 to 4 cm partially disabling tremor.
Grade IV: Severe disabling tremor with an amplitude of more than 4 cm.
Diagnostic criteria for idiopathic tremor
Idiopathic tremor diagnostic criteria proposed by the American Movement Disorders Society and the World Tremor Research Organization
(1) Core diagnostic criteria.
①Motor tremor of both hands and forearms.
(2) No other neurological signs except gearing.
③Or only head tremor without dystonia.
(2) Secondary diagnostic criteria.
①The duration of the disease is more than 3 years.
② Family history.
③ Tremor is reduced after drinking alcohol.
(3) Exclusion criteria.
(1) With other neurological signs, or a history of trauma shortly before the onset of tremor.
(2) Physiological hyperactive tremor caused by drugs, anxiety, depression, hyperthyroidism, etc.
③History of psychogenic (psychogenic) tremor.
④Sudden onset or segmental progression.
⑤Primary erect tremor.
⑥Position-specific or target-specific tremor only, including occupational tremor and primary writing tremor.
(vii) Treatment options for verbal tongue-chin or leg tremor only.
Most patients with idiopathic tremor have only mild tremor, and only 0.5% to 11.1% of patients require treatment. The following treatment measures are available for those with significant symptoms.
Drinking small amounts of alcohol to reduce tremor
The majority of patients who drink a small amount of alcohol may experience significant temporary relief of tremor but may need to increase the amount of alcohol consumed over time to achieve the same effect. It is recommended that patients drink a small amount of alcohol before meals or social activities to reduce tremor.
Long-term use of drugs
Beta-adrenergic blocking drugs can act by blocking peripheral beta2 receptors Propranolol (Prostaglandin) can reduce the amplitude of tremor has no effect on the frequency of tremor, and needs to be taken for a long time. In a specific situation tremor obvious people can be pre-temporary application of 30 to 90mg in 3 doses.
Or with Aurolol 10mg fire, 3 times / d propranolol (tipsan) relative contraindications include: uncontrolled heart failure; II to III degree atrioventricular block; asthma and other bronchospastic disease; insulin-dependent diabetes because propranolol (tipsan) can block the normal adrenergic response to hypoglycemia in diabetic patients. Rare side effects include fatigue nausea diarrhea, rash, impotence and depression etc. Most patients tolerate propranolol (Propranolol) well, it is still recommended to monitor pulse and blood pressure during the use of the drug pulse rate remains above 60 beats / min is usually safe.
Antispasmodics and tranquilizers
(1) paracetamol (paroxetine): can reduce the amplitude of tremor, does not affect the frequency of tremor, the mechanism is unknown, used to reduce hand tremor, the efficacy of the head tongue tremor ET patients are often very sensitive to this drug, not according to the treatment of epilepsy, from a small dose of 50mg / d every 2 weeks to increase the dosage of 50mg / d, until effective or the emergence of side effects, usually effective dose of 100-150mg, 3 times / d Health search to improve medication compliance to reduce drowsiness side effects recommended to be taken before bedtime 20% to 30% of patients with acute side effects such as vertigo, nausea and postural instability after taking the drug temporary, can be gradually alleviated, does not affect the continued use of drugs.
(2) Anti-epileptic drug gabapentin (gabapentin): for the treatment of idiopathic tremor is still controversial. Although several open studies suggest that gabapentin is effective in reducing tremor, a double-blind controlled study did not find it to be more effective than placebo
(3) Neuroleptics: Phenobarbital, diazepam (Valium), etc. are commonly used. Recent studies suggest that clonazepam (clonidine) may have better efficacy, with side effects mainly drowsiness. Anxiety can aggravate tremor so it is speculated that the treatment mechanism may be related to the central sedative effect.
Botulinum toxin A
Botulinum toxin A (BTX-A) is effective in reducing tremor in the limbs and soft palate to reduce tremor amplitude, with little effect on tremor frequency. In one observation, BTX-A was injected into the extensor and flexor muscles of the hand for 4 weeks in 75% of patients with mild to moderate relief of tremor.
BTX-A can also treat primary verbal tremor. Blitzer et al. injected BTX-A subcutaneously into the vocal folds of patients via the cricothyroid membrane, and most patients showed significant improvement in vocal function; some patients required re-injection into the sternocleidomastoid and sternocleidomastoid muscles. The mechanism may act on peripheral nerve endings to block the release of the neurotransmitter acetylcholine. Attention should be paid to the individualization of injection dose and site.
Others
(1) Clozapine: It is effective in relieving idiopathic tremor, but because it can cause granulocytopenia and lead to fatal infection, it is recommended to check blood counts weekly for 6 months and then every 2 weeks.
(2) carbonic anhydrase inhibitor vincristine (methazolamide): can effectively reduce tremor, especially head and speech tremor average maximum dose 200mg/d common side effects such as drowsiness, nausea anorexia numbness and abnormal sensation
(3) calcium antagonists: flunarizine 100mg/d health search or nimodipine 30mg, 4 times/d can reduce tremor in some patients, but the efficacy is still controversial.
(4) Methylxanthine derivatives: In the past, it was thought that theophylline (theophyl-sr) could induce or even aggravate the disease, and one study improved tremor after 4 weeks with theophylline, which needs further confirmation.
(5) Theophyl-sr: 50-100 mg, 3 times/d.
The recommended treatment plan abroad is to first try paracetamol (paroxetine) 50mg in the evening, which can be increased to 125-250mg according to the condition; if necessary, switch to or combine with long-acting propranolol (insulin) 40mg in the morning, and increase the dose according to the condition.
Surgical treatment
Patients with idiopathic tremor can try surgical procedures after regular drug treatment, but still cannot completely eliminate the tremor, including.
(1) Stereotactic thalamic disruption: the best target is the ventral median nucleus or ventral lateral nucleus of the thalamus Unilateral thalamic disruption can relieve more than 90% of patients with tremor Safe and effective drug therapy is ineffective in severe lateralized tremor can be applied. 10% of ET patients with postoperative dysarthria balance disorder, contralateral limb weakness cognitive impairment and epilepsy, mortality rate <0.5%, radiofrequency disruption is safer than cerebral white matter dissection and thalamic chemical The radiofrequency disruption is safer than cerebral white matter dissection and thalamic chemical disruption.
(2) Deep brain stimulation (DBS): It is a new surgical treatment to control tremor by implanting miniature pulse generators in the ventral nucleus of the thalamus, generally using 135-185 times/s high-frequency stimulation pulses 60-120 μs wave amplitude 1-3V, interfering and blocking the electrophysiological activity of neurons without destroying the thalamic nucleus.
DBS is more effective for resting and postural tremor than for motor tremor, more effective for distal limb tremor than for proximal limb and trunk, and less effective for head and speech tremor. Bilateral stimulation is possible with less damage and fewer long-term side effects. The disadvantage is that the cost is expensive.
Warm tip: please combine the specific medication with clinical, by the doctor interview guidance shall prevail.